Lance with conduits for mixing gases located interiorly



July 10, 1962 w. v. BERRY 3,043,577

LANCE WITH CONDUITS FOR MIXING GASES LOCATED INTERIORLY Filed Oct. 20,1960 2 Sheets-Sheet 1 INVENTOR Walter V. Berry July 10, 1962 w. v. BERRYLANCE WITH CONDUITS FOR MIXING GASES LOCATED INTERIORLY Filed Oct. 20,1960 2 Sheets-Sheet 2 INVENTOR Wulier V- Berry i is 3,043,577 LANCE WITHC(INDUITS FOR MIXING GASES LOCATED INTERIQRLY Walter V. Berry 2679 SantaBarbara Dfive,

Pittsburgh 34, Pa. Filed on. 20, 1960, Ser. No. 63,877 4 Cls. (Cl.266-34) My invention relates to apparatus for discharging a gas jet andmore particularly to a lancefor injecting fuel gas and oxygen into anopen hearth furnace for making steel.

In the making of steel it has been found to be advantageous to introduceoxygen and a combustible gas, such as natural gas, directly against thesurface of the melt. Usually this is done in two operations. First acombination of fuel gas and oxygen are introduced into the furnace so asto produce a hot flame and a large amount of heat quickly in order toreduce the cold metal charge to a melted condition rapidly. After themetal has been melted and hot metal has been added it is then desirableto shut off the fuel gas and inject only oxygen into the melt for thepurpose of reducing carbon to the desired point in preparation fortapping the furnace. I

' believe that this can best be done by a combination device comprisinga burner mechanism whereby the gas and oxygen willbe mixed together toform a blue flame when they are both being ejected together. By shuttingoff the fuel gas and injecting only oxygen into the burner mechanism,the burner mechanism also serves as an oxygen lance.

Since the temperature in the furnace is sulficiently high to melt themetal of the lance it has been found necessary to provide cooling meansin the lance preferably by the use of water circulating therein.However, in spite of all the attempts in the prior art to cool thelance, there continues to be a rapid deterioration at the nose of thelance around the holes from which the oxygen is ejected intothe furnace.I have concluded that this is due to the combination of heat in thefurnace together with the presence of large quantities of free oxygenwhich are being forced against the metal. In an effort to solve this,several different types of materials have been employed such as some ofthe highly temperature resistant and oxidation resistant materials suchas have been experimented with in rockets. These have all proven to beunsatisfactory because they oxidize and otherwise deterioratesubstantially as rapidly as copper. I therefore conclude that thesolution to the problem lies in redesigning the lance while continuingto employ' copper which has a relatively low melting point. I haveaccomplished this by two approaches. First I have conceived a way togain better circulation of cooling water in the region of the oxygen andfuel gas conduits at the nose of the lance and secondly, surprisingthough it may sound, I have found that by moving the flame into theinterior of the lance I get less deterioration than if the flame isentirely outside of the lance.

Accordingly, it is an object of my invention to provide a lance forinjecting fuel gas and oxygen into a furnace which produces a maximum ofcombustion.

-It is another object of my invention to provide an improved lance whichhas a circulating flow of #water in such a manner as to preventdeterioration of the lance due to heat.

It is another object of my improved injection burner.

It is another object of my invention to remove dangerous flashbackcharacteristic of premixing devices.

It is another object of my invention to provide for an increase in thepercentage of cold metal charge which is practical.

invention to provide an It is another object of my invention to decreasepercentage of hot metal charge necessary.

It is another object of my invention to reduce tap to tap time andthereby increase production.

it is another object of my invention to provide an improved nozzle.

It is an ancillary object of my invention to provide an improved gasejection device.

The novel features that I consider characteristic of my invention areset forth with particularity in the appended claims. The inventionitself, however, both as to its organization and its method ofoperation, together with additional objects andadvantages thereof, willbest be understood from the following description when read inconnection with the accompanying drawings in which:

FIGURE 1 is a showing in cross section of the nozzle end of a lance inaccordance with the preferred embodiment of my invention.

FIGURE 2 is an end view of the lance shown in FIGURE 1.

FIGURE 3 is a transverse cross section taken on the line III--III ofFIGURE 1.

FIGURE 4 is a showing in cross section of a portion of a lance inaccordance with one embodiment of my invention wherein the separatorbetween fuel gas and oxygen conduits at their junction is tapered.

FIGURE 5 is a showing in cross section of a portion of a nozzle inaccordance with another embodiment of my invention wherein both theoutside walls and the separator are tapered.

In accordance with the preferred embodiment of my invention I provide alance for injecting fuelgas and oxygen into an open hearth furnacewhereby the lance extends through the ceiling of the furnace down intothe interior thereof to a point which is a short distance above thesurface of the material being treated therein.

The lance comprises a shank 6 and a nozzle 8. The shank 6 comprises fourcylindrical pipes which are concentric and located in spacedrelationship to each other. These pipes comprise an inner oxygen pipe10, an inner water jacket 12 around said oxygen pipe a water deflectorpipe 14 around said inner water jacket 12 and an outer water jacket 16around said water deflector pipe 14. g

The nozzle 8 which is attachedto the end of the shank 6 and has the sameoutside diameter as the shank 6 comprises six pairs of terminal conduitseach of which conduits is one half inch in diameter and extends outwardat an angle of approximately in the prefered embodiment or between 20and in accordance with other embodiments of my invention, from the axisof the lance. Each pair of terminal conduits comprises an inner terminalconduit 18 and an outer terminal conduit 20,

the axis of each conduit of each pair of conduits lying in the sameplane as the other and as the axis of the lance. The said inner terminalconduits are all joined together, at theirupper extremity toward theshank of the lance, into a common larger conduit 22 referred to hereinas the large oxygen conduit. The large oxygen conduit 22 which isconnected to the smaller inner terminal conduits 18 extends upward andis connected to the inner oxygen pipe 10 of the lance shank '6.

The outer terminal conduits 20' change direction at the point where theinner terminal conduits 18 are connected to the larger innerconduit andextend upward parallel to the axis of the lance adjacent to the largeoxygen conduit 22.

The terminal conduits are joined together by spacers extending betweeneach pair of terminal conduits so as to fill the space between adjacentpairs of conduits. The spacers are so formed so as to provide, inconjunction with the inner Walls of the inner terminal conduits 18, an

E inverted cone shaped indentation 30 in the nose of the cone.

The nozzle also comprises an outer cylindrical water jacket 26 which hasan axis co-lineal with the axis of the shank of the lance. The outerwater jacket 26 extends inward at the nose of the nozzle in a curvedmanner so as to contact the terminal conduits and the spacerstherebetween so as to form a watertight junction therebetween and toproduce a cup shaped nose 28 broken only by the inverted cone shapedindentation 30' in the nose and the terminal conduit ejection chamberdescribed hereinafter.

Each pair of the terminal conduits comprises two parallel conduitshaving a common wall. The said wall between the. two conduits of eachpair of terminal conduits is preferably inch thick and the conduits arepreferably /2 inch. in diameter.

The wall between the terminalconduits of each pair is cutaway for adepth of one inch or a distance equal to the sum of the diameters of thetwo conduits from the end of the nozzle, so as to form a terminalconduit ejection chamber 31. The terminal conduit ejection chambers havewalls that are rounded or smoothed off so that the cross section issubstantially an oblong space having parallel sides and rounded ends. Inother words, in accordance with a preferred embodiment of my inventionthe ejection chamber is formed by cutting away the walls between thepairs of conduits from lines on the wall of the outer conduits which are90 from a perpendicular line between the axis ofthe outer and the innerconduit,

and which are parallel to the axis of the outer conduit, through to acorresponding line on the inner conduit.

The water jacket of the nozzle is of the same diameter as the outerwater jacket pipe of the shank and the two are joined together so theaxis of one is an extension of the axis of t-he'other. The inner waterpipe 12 has a diameter equal to the outer edges or walls of oppositelydisposed outer conduits 20 at the termination of the outer conduits 20toward the shank. The inner water pipe 12 of the shank is fastened tothe outer walls of the outer conduits in a gas and water tight junction32. The water deflector pipe 14 extends between the outer water jacket16 and the inner water jacket 12 co-axially therewith and in spacedrelationship thereto and extends into said nose to' a pointapproximately opposite the region where the inner terminal conduits 18are joined together into the large inner oxygen conduit In the operationof the device in accordance with the 7 preferred embodiment of 'myinvention, oxygen is injected terhtinal conduits 18 to the terminalejection chamber 31.

A fuel gas, such as natural gas, is injected into the region between theinner-oxygen'pipe 10 and the inner-water jacket 12 flowing down throughthe lance and out through the outer terminal conduits 20 to the terminalconduit ejection chamber 31. In the terminal conduit ejection chamber 31the two gases mix together and combustion occurs. The flame thusproduced begins in the ejection chamber 31 and extends fora distance ofone to three feet beyond the end of the lance. I have found that withthis arrangement a good blue flame is obtained which is well seatedinside the ejection chamber 31. I have also found on experimentationthat the device does not operate as 'well if the oxygen and fuel gas arereversed. A better flame is obtained if the oxygen and the fuelgas areinjected as described above although the device is operable if thegasses are reversed.

' Wateris injected into the region between the innerw-ater jacket 12 andthe water deflector pipe 14 and flows down to the nose 28 of the lancecoming in contact with the inside of the metal spacers between theconduits and flows back up' along the outer wall,26 of the lance. I havefound that by this configuration a constant and continuous flow of wateris directed against the walls that need to be cooled. Devices in theprior art have employed e of the hole.

noses which were either fiat or only slightly indented, whereby therewas no direct flow ofwater between the terminal conduits 12, 20 in theregion behind the center of the nose 30, therefore, a great deal ofturbulence was pro-. duced and very poor circulation. By effectivelyraising the indentation 30- in the nose up to where it is effectivelycoextensive with the walls of the terminal conduits 18, 20 I am able toget water to how smoothly and continuously along the walls of the nosewithout turbulence and thereby obtain a better cooling effect than istrue in fuel gas-oxygen burners of the prior art.

It will be noted that the biggest problem in constructing a lance ofthis type is finding a way to combat the tendency of the metals tooxidize around the conduit openings in the nose. This oxidation is dueto the tremendous temperatures involved together with the presence of alarge quantity of pure oxygen. I have found that with the device asdescribed herein the rate of deterioration is greatly reduced. I believethat this is partially due to the fact that by the time the oxygenreaches the outer surface of the nose of the lance it is no longer pureoxygen, but is mixed with fuel gas. Since it is at the outer surface ofthe lance nose Where the greatest heat is involved, that is the placewhere oxidation is most'likely to occur. Since the oxygen is mixed withfuel gas at that point there is less deterioration at the surface of thenose because effectively the fuel gas shields the nose from half of theoxygen.

It should be noted that we have overcome the problem of deterioration byeffectively jumping from the frying pan into the fire. We have moved thefire from outside of the lance into the interior of the lance andthereby produced less damage to the lance than was present with the fireoutside of the lance. This is a surprising result. However, we havefound in practice that a drastic improvement is produced by thisconstruction.

It should also be noted that'in the construction of the device inaccordance with the preferred embodiment of my invention, the flamebegins inside the lance. There will therefore be a tendency of the flameinside of the ejection chamber of the lance to heat the walls of thechamber. It is therefore important thatthe walls of the ejection chamberbe cooled as much as possible. For that reason it became even moreimportant to find a better cooling system, which need sparked part ofthis invention.

In accordance with other embodiments of my invention as shown in FIG. 5,I provide pairs of terminal conduits opening into an ejection chamberwhereby the terminal conduits of each pair near their termination in theejec-' tion chamber are sloped toward each other at approximately 15from the parallel position. The terminal conduits and the outer walls ofthe ejection chamber are also tapered inward toward the nose so that theouter walls of the ejection chamber form substantially an extension ofthe line along the walls of the terminal conduits in the region neartheir connection with the ejection chamber. Thus the end of the ejectionchamber toward the end of the nose of the lance is substantially smallerthan the cross section-a1 area of the ejection chamber in the regionwhere it is connected to the two conduits. I have found that thisembodiment is advantageous in situations where a substantial amount ofdifficulty is encountered due to splashing of slag and other materialsin the furnace against the nose of the lance. By restricting the size ofthe opening at the surface ofthe lance nose to,

increase the pressure of the oxygen at the surface of the lance so thatit tends to blow'away foreign materialfrom the entrance intothe ejectionchamber, I thereby discourage the slag or other mat'er'i plugging partBy this arrangement eliminate the proble'm that has been encounteredwith the gas terminal conduit becoming plugged with slag when no gas isbeing injected into the lance, i.e., when. the lance is be ing employedsolely as an oxygen lance. As was ex-' pla-ined above, this lance ispreferably used in a cycle whereby fuel gas and oxygen are employedtogether until suificient heat is produced in the furnace, then the fuelgas is shut oif and oxygen alone is fed through the lance for reducingthe carbon in the melt. It is while the lance is being employed purelyas an oxygen lance that there is a tendency for the slag to move up intothe ejection chamber and to plug the end of the fuel gas terminalconduit.

In accordance with another embodiment of my invention, as shown in FIG.4, I provide two terminal conduits extending parallel to each other andopening into an ejection chamber, the outer walls of which are parallelto the outer walls of the conduits. The two conduits are separated by acommon wall which is tapered from a point approximately one inch fromthe ejection chamber to a point at their termination in the ejectionchamber. I have found that this embodiment has some tendency to preventslag from entering the fuel gas conduit when oxygen alone is being fedthrough the lance. By having the inner wall tapered the oxygen tends tospread out into a stream of a larger cross section so that itsubstantially fills the exit opening of the ejection chamber at thesurface of the nose. By having the inner wall tapered it also provides avelocity component in the oxygen stream which is perpendicular to themain direction of flow of oxygen through the terminal conduit.

In FIGURES 4 and 5 references to identical part-s shown in FIGURES 1-3are the same with a prime and double prime fixed thereto respectively.

Although I have shown and described specific embodiments of myinvention, I am aware that other modifications thereof are possible; myinvention, therefore, is not to be restricted except insofar as isnecessitated by the prior art and the spirit of the invention.

I claim as my invention:

1. A lance comprising an inverted cone shaped shell, a substantiallyflat disc surrounding the base of said cone e and forming an extensionof the edges of said cone, said disc having a plurality of oblong holesthere through, the holes being divided by a thin wall extending inwardlyfrom a point distant from the surface of said disc approximately equalto the long dimension of said holes as measured on the surface of saiddisc.

2. A nozzle comprising a cup-shaped, nose, a plurality of pairedconduits extending through said nozzle end, each 'pair of said conduitsending in an enlarged common indentation in said nose, said commonindentation being in' depth equal approximately to the sum of thediameters of the said pair of conduits connected thereto.

3. An oxygen fuel gas lance comprising a nose piece having anindentation therein, said indentation being of tapered cross sectionwith its larger end toward the surface of said nose piece, a pair ofconduits inside said lance terminating in said indentation a substantialdistance from the surface of said nose piece, said conduits, at the endsthereof, being oriented so that the extensions of their axes converge ashort distance beyond the end of the nose of the lance.

4. A fuel gas and oxygen lance comprising two parallel conduitsextending to the surface of the nose of the lance, said conduits havinga common wall therebetween, said partition being tapered atapproximately 15 from a point deep in the interior of the lance, so afine line at its termination at a point located a distance from the noseof the lance approximately equal to the sum of the diameters of the saidconduits. 7

References Cited in the file of this patent UNITED STATES PATENTS1,949,731 Soldatorf Mar. 6, 1934 2,807,506 Gehring Sept. 24, 19572,863,656 Cox Dec. 9, 1958 2,937,864 Kesterton May 24, 1960 UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Pat. No. 3,043,577 July10, 1962 Walter V. Berry It is hereby certified that error appears inthe above numbered patent requiring correction and that the said LettersPatent should read as corrected below.

Column 6, line 26, for "so" read to Signed and sealed this 23rd day ofOctober 1962.

(SEAL) Attest:

ERNEST w. SWIDER DAVID L LADD Attcsting Officer Commissioner of Patents

